Gun barrel and firing mechanism for impact-actuated underwater guns

ABSTRACT

An improved gun barrel and firing mechanism or &#39;&#39;&#39;&#39;power head&#39;&#39;&#39;&#39; for use in association with a thrust pole, spear of the like as an impact-actuated underwater gun. The firing mechanism comprises a relatively movable detonating plunger removably coaxially attachable to a thrust pole or the like at one end and carrying a firing pin at the other end which is operative to detonate a cartridge fitted in the gun barrel upon impact of the barrel muzzle, due to the momentum of said pole member in overriding the outward thrust of a compression spring acting between the gun barrel and the detonating plunger. A safety lock pin serves to retain the detonating plunger and its associated thrust pole in its relatively outward, non-detonating position until such time as the gun is to be used.

United States Patent [191 Mounier Mar. 18, 1975 GUN BARREL AND FIRING MECHANISM FOR IMPACT-ACTUATED UNDERWATER GUNS [76] Inventor: Bruce A. Mounier, 9321 S.W. 80th Ter., Miami, Fla. 33143 [22] Filed: Oct. 9, 1973 [21] Appl. N0.: 404,499

Primary E.\'aminerBenjamin A. Borchelt Assistant E.\'aminer-C. T. Jordan Attorney, Agent, or FirmErnest H. Schmidt [57] ABSTRACT An improved gun barrel and firing mechanism or power head for use in association with a thrust pole, spear of the like as an impact-actuated underwater gun. The firing mechanism comprises a relatively movable detonating plunger removably coa-xially attachable to a thrust pole .or the like at one end and carrying a firing pin at the other end which is operative to detonate a cartridge fitted in the gun barrel upon impact of the barrel muzzle, due to the momentum of said pole member in overriding the outward thrust of a compression spring acting between the gun barrel and the detonating plunger. A safety lock pin serves to retain the detonating plunger and its associated thrust pole in its relatively outward, non-detonating position until such time as the gun is to be used.

3 Claims, 4 Drawing Figures I M 1522 3'4 2? 2/ Z7 26 3 5 29 0 A? 27 as GUN BARREL AND FIRING MECHANISM FOR lMPACT-ACTUATED UNDERWATER GUNS This invention relates to firearms and is directed particularly to a firing mechanism including means for removable attachment to a thrust pole, spear or the like, for manual or powered thrust as a spear gun for underwater use in killing large fish or sharks.

lmpact actuated guns for use in underwater killing or disabling large fish arev known. In my US Pat. No. 3,664,052, issued May 23, 1972, there is disclosed an impact-actuated underwater gun comprising a pole member used as a handle to be thrust against the fish to be shot and having a comparatively short gun barrel assembly or power head at the striking end wherein a weighted firing pin, arranged behind the cartridge and spaced therefrom by a compression spring, is carried foreward by its momentum upon striking the fish with the muzzle, thereby firing the cartridge. The principal object of this invention is to provide a novel and improved gun barrel and firing mechanism for such impactactuated underwater guns.

A more particular object of the invention is to provide a gun muzzle and firing mechanism for impactactuated guns wherein the associated pole member, instead of being fixed with respect to the gun barrel, is arranged for limited axial movement with respect thereto together with a detonating plunger comprising the firing mechanism, the plunger having a firing pin at its inner end normally spaced from the detonating end of the cartridge fixed within the gun barrel, and being adapted to detonate it when carried foreward by the momentum of the pole member upon striking a fish or other object with the gun barrel muzzle.

Another object is to provide a gun muzzle and firing mechanism for impact actuated underwater guns of the character described including a novel and improved safety lock pin which must be physically removed from the gun to enable firing.

Another object is to provide a gun barrel and firing mechanism for underwater impact-actuated gun which is simple in structure, economical to manufacture, safe and dependable in operation, and durable in use.

Other objects, features, and advantages of the invention will be apparent from the following description when read with reference to the accompanying drawings. In the drawings, wherein like reference numerals denote corresponding parts throughout the several views:

FIG. I is a side elevational view of an impact actuated spear gun assembly embodying the invention, with the rear portion of the removable shaft broken away;

FIG 2 is a longitudinl cross-sectional view of the gun barrel and firing mechanism taken along the line 22 of FIG. 1 in the direction of the arrows;

FIG. 3 is a vertical cross-sectional view taken along the line 33 of FIG. 2 in the direction of the arrows; and

FIG. 4 is a partial enlargement of a portion of FIG. 2.

Referring now in detail to the drawings, which illustrate a preferred embodiment of my invention, the same comprises, genrally, a cylindrical breech member 11, a detonating plunger 12 reciprocatively received in the rearward end of said breech member, and a gun barrel l3 removably attached at its rearward end to the forward end of said breech member, said breech memher, said detonating plunger and said gun barrel all preferably being machined of a strong, hardened stainless steel. The gun barrel and tiring mechanism also comprises a safety lock pin 14, and is provided with means for removably attaching a spear shaft 15, as is hereinafter more particularly defined.

The breech member 11 is formed at its forward end with an internally threaded, blind, coaxial bore 16 defining at its inner end a transverse, circular anvil surface l7. The outer, forward edge ofthe breech member 11 is peripherally beveled, as indicated at 18.

The rearward end of the breech member 11 is formed with a blind, coaxial bore 19 for sliding fit therein of the cylindrical detonating plunger 12. A central, coaxially extending, reduced diameter firing pin bore 20 in the breech member 11 communicates between the forward and rearward bores 16 and 19, respectively.

Te breech member 11 is also provided with a diametrically extending, transverse, through bore 21 for the purpose hereinafter appearing. A small transverse vent opening 22 extends from the outer wall of the breech member 11 to communicate with the detonating plunger bore 19 at a position just rearwardly of te bottom surface of said bore. The rearward end portion of the breech member 11 is preferably externally tapered, as indicated at 23.

The inner end of the gun barrel 13 is externally threaded, as indicated at 24, for cooperative engagement with the internally threaded axial bore 16 in the breech member 11. The outer end of the externally threaded inner end of the gun barrel is beveled, as indicated at 25, for the purpose hereinafter appearing. The inner end of the gun barrel 13 is also formed with a shell bore 26 merging with reduced-diameter forward end bore portion 27 for slidingly receiving, in closefitting engagement therein, a cartridge C to be fired. The end 27 of the shell bore merges into a slug bore 28 which is convergently tapered in the direction of the muzzle or forward end of the gun barrel. As indicated at 29, that portion of the gun barrel peripherally surrounding the slug bore 28 preferably is somewhat reduced in outside dimeter for weight reduction purposes. The reduced diameter portion 29 extends somewhat short of the muzzle end of the gun barrel to provide an enlarged muzzle portion 30 thereat.

The inner end of the externally threaded end portion 24 of the gun barrel 13 defines an annular shoulder 31 seating an O-ring 32. The length of the inter-fitting threads between the breech member 11 and the gun barrel 11 is such that, with a cartridge C fitted in place to be tired as illustrated in FIG. 2, when the gun barrel is threaded home within the breech member 11 so that the shell flange is securely clamped against the anvil surface 17, the forward edge of said breech member will tightly compress the O-ring 32 against its barrel seat shoulder 31 to seal against the entrance of water to the underside of a cartridge shell locating flange. A lock nut or ring could also be used to prevent loosenmg.

The cylindrical detonating plunger 12 is integrally formed at its forward end with a short, coaxial, reduced-diameter portion 33 extending into a forwardly directed, central firing pin 34 of such size as to be freely received within the firing pin opening 20 of the breech member 11. The reduced-diameter front end portion 33 of the detonating plunger 12 defines. therewith an annular shoulder 35 adapted to receive, coaxially seated thereon, one end of a helical compression spring 36 the other end of which seats against the bottom of the plunger bore 19 in the breech member 11. The compression spring 36, being constrained between the inner end of the detonating pluner l2 and the breech member 11, serves to normally yieldingly urge said detonating plunger at the outermost of two limit positions with respect to said breech member, whereat its firing pin 34 will be maintained in withdrawn position with respect to an assembled cartridge C. The outermost limit position of the detonating plunger 12 is established by the use of a resilient sleeve friction pin 38 press-fitted within a transverse bore 37 in said detonating plunger 12, outwardly-extending end portions of which abuttingly engage rearward zone portions of the transverse through bore 21 at the opposite opposed ends thereof (see FIGS. 1 and 2). The diameter of the transverse through bore 21 is so large as compared with the diameter of the resilient sleeve pin 38 as to permit sufficient forward movement of the detonating plunger 12 within the breech member 11 against the reactive force of the compression spring 36 as will permit the firing pin 34 to strike and detonate an assembled shell C when the gun is fired as hereinafter described.

Safety lock means is provided for securely retaining the detonating plunger 12 in its fully withdrawn limit position with respect to the breech member 11 so as to minimize the possibility of accidental firing of the gun. To this end, the detonating plunger 12 is provided with a dimetrically-extending transverse lock pin opening 39 immediately rearward of the rearward end of the breech member 11 when said detonating plunger is in its outwardmost limit position as illustrated in FIGS. 1 and 2. The safety lock pin 14 is formed with a straight leg portion 14a receivable in the lock pin opening 39 and removably retained therein, as best illustrated in FIG. 3, by a curved safety lock leg portion 14b bent to yieldingly embrace an arcuate outer surface portion of the detonating plunger 12 for retention in place. It will be understood that in preparing the gun in readiness for firing, the safety lock pin 14 will be withdrawn from the lock pin opening 39 to permit the required forward movement of said detonating plunger with the breech member 11. The gun can then be fired by thrusting it so that the muzzle end strikes as squarely as possible against the body of the fish, preferably near the vital organs, with such force that the momentum imparted to the spear shaft 15 and its associated detonating plunger 12 will carry the firing pin 34 forward within the firing pin bore to impinge the firing pin tip against the central detonating element of the cartridge C.

Although I have illustrated and described my gun barrel and firing mechanism for impact-actuated underwater guns in association with a spear shaft 15 for use as a manual thrust spear gun, it will be understood that the power head invention is as well adaptable to use with other underwater projecting means, such as bow, sling or the like power thrust devices driven by compression springs, rubber bands, compressed gas or explosive shells, for example. An important feature of my invention resides in the fact that simply by changing the compression spring 36, the gun barrel and firing mechanism or power head" can readily be adapted to use with any ofsuch varied projecting or impelling devices. Thus, if instead of being used with a manuallypropelled spear shaft 15 as illustrated the device is attached for use with a power sling activated by pressur- 4 ized gas imparting a relatively high initial impact to the gun assembly, the compression spring 36 will be re placed by a similar spring of somewhat greater strength to minimize any possibility of premature detonation due to high initial acceleration of the detonating plunger 12 upon firing of the gun.

While I have illustrated and described herein only one form in which the invention can conveniently be embodied in practice, it is to be understood that this form is present by way of example only and not in a limiting sense. The invention, in brief, comprises all the embodiments and modifications coming within the scope and spirit of the following claims.

What I claim as new and desire to secure by Letters Patent is:

l. A gun barrel and firing mechanism for impactactuated underwater guns comprising, in combination, a breech member, an axial bore in one end of said breech member, a cylindrical detonating plunger one end of which is slidingly received in said axial breech member bore, means constraining the relative sliding of said detonating plunger with respect to said breech member to movement between inner and outer limit positions, means resiliently constraining said detonating plunger at said outermost limit position with respect to said breech member, the inner end of said detonating plunger having an outwardly extending, reduceddiameter firing pin, the other end of said breech member providing at its other end an anvil surface for seating the firing end of a cartridge having a peripheral flange, a tubular gun barrel having a through bore, means for removably attaching one end of said barrel coaxially with respect to said other end of said breech member, a coaxial firing pin opening communicating between the inner end of said axial breech member bore and said anvil surface, said through bore opening at said one end of said barrel being such as to slidingly receive a cartridge to be fired, said firing pin being of such size as to be receivable through said firing pin opening, the length of said firing pin with respect to the length of said firing pin opening being such that upon said detonating plunger reaching its innermost limit position with respect to said breech member said firing pin will move into detonating position with respect to a cartridge seated on said anvil surface, removable safety lock means for locking said detonating plunger at said outermost limit position with respect to said breech member to prevent accidental detonating of a cartridge seated on said anvil surface, said means constraining the relative sliding of said detonating plunger with respect to said breech member to movement between said inner and outer limit positions comprising a transverse, diametrically extending through bore near said one end of said breech member and intersecting said axial breech member bore, a transverse, diametrically extending bore in said detonating plunger near the inner end thereof, and a resilient sleeve pin friction fitted in said transverse detonating plunger bore and having outer end portions extending through opposite ends of said transverse breech member bore, said breech member bore being of substantially greater diameter than that of said transverse detonating plunger bore.

2. A gun barrel and firing mechanism for impactactuated underwater guns as defined in claim 1, wherein said detonating plunger resiliently constraining means comprises a helical compression spring constrained between the inner end of said breech member bined mass of said breech member, detonating plunger and gun barrel, whereby, upon striking of the muzzle end of said gun barrel against an object to be fired upon, the momentum of said spear shaft will carry said detonating pin into firing position with respect to a cartridge seated against said anvil surface against the reactive force of said helical compression spring. 

1. A gun barrel and firing mechanism for impact-actuated underwater guns comprising, in combination, a breech member, an axial bore in one end of said breech member, a cylindrical detonating plunger one end of which is slidingly received in said axial breech member bore, means constraining the relative sliding of said detonating plunger with respect to said breech member to movement between inner and outer limit positions, means resiliently constraining said detonating plunger at said outermost limit position with respect to said breech member, the inner end of said detonating plunger having an outwardly extending, reduced-diameter firing pin, the other end of said breech member providing at its other end an anvil surface for seating the firing end of a cartridge having a peripheral flange, a tubular gun barrel having a through bore, means for removably attaching one end of said barrel coaxially with respect to said other end of said breech member, a coaxial firing pin opening communicating between the inner end of said axial breech member bore and said anvil surface, said through bore opening at said one end of said barrel being such as to slidingly receive a cartridge to be fired, said firing pin being of such size as to be receivable through said firing pin opening, the length of said firing pin with respect to the length of said firing pin opening being such that upon said detonating plunger reaching its innermost limit position with respect to said breech member said firing pin will move into detonating position with respect to a cartridge seated on said anvil surface, removable safety lock means for locking said detonating plunger at said outermost limit position with respect to said breech member to prevent accidental detonating of a cartridge seated on said anvil surface, said means constraining the relative sliding of said detonating plunger with respect to said breech member to movement between said inner and outer limit positions comprising a transverse, diametrically extending through bore near said one end of said breech member and intersecting said axial breech member bore, a transverse, diametrically extending bore in said detonating plunger near the inner end thereof, and a resilient sleeve pin friction fitted in said transverse detonating plunger bore and having outer end portions extending through opposite ends of said transverse breech member bore, said breech member bore being of substantially greater diameter than that of said transverse detonating plunger bore.
 2. A gun barrel and firing mechanism for impact-actuated underwater guns as defined in claim 1, wherein said detonating plunger resiliently constraining means comprises a helical compression spring constrained between the inner end of said breech member axial bore and the inner end of said detonating plunger in surrounding relation with respect to said firing pin.
 3. A gun barrel and firing mechanism for impact-actuated underwater guns as defined in claim 1, including a comparatively long spear shaft coaxially removably affixed to the outer end of said detonating plunger, wherein said spear shaft is of solid metal construction exhibiting substantial mass as compared with the combined mass of said breech member, detonating plunger and gun barrel, whereby, upon striking of the muzzle end of said gun barrel against an object to be fired upon, the momentum of said spear shaft will carry said detonating pin into firing position with respect to a cartridge seated against said anvil surface against the reactive force of said helical compression spring. 